Field of Invention
The present invention belongs to the technical field of electromagnetically functional devices, focuses on fast dynamically functional devices for terahertz band, and is adapted for terahertz wave modulators, terahertz wave switches, and terahertz wave phase shifter.
Description of Related Arts
As one of the most important core technologies in the terahertz communication system, the terahertz wave dynamically functional device, such as the terahertz external modulator now becomes the focus of terahertz science and technology research. At present, the terahertz external modulator is studied internationally through quasi-optical method, and however, this method is large in insertion loss, more in unit structures, and difficult to increase the modulation rate. Therefore, the fast modulation of terahertz waves transmitted in space has not been achieved so far. Chinese Patent No. 201510894480.5 disclosed a terahertz wave fast modulator based on coplanar waveguide combining with transistor, which comprises an input straight waveguide, a coplanar waveguide and an output straight waveguide, wherein the coplanar waveguide comprises a substrate and a feeder unit located on the substrate; the feeder unit comprises an input section, a transmission section and an output section; the transmission section comprises a central feeder and two resonant feeders respectively located at two sides of the central feeder; the input section of the feeder unit is set in the input straight waveguide, the output section thereof is set in the output straight waveguide; a voltage input wire is externally connected with the central feeder of the coplanar waveguide; at least one modulation unit with high electron mobility transistor is set between the resonant feeders and the central feeder; a modulation unit with high electron mobility transistor is switched on/off through an external voltage. The above modulator can control transmission characteristics of the terahertz waves transmitted on coplanar waveguide microstrips, so as to achieve the high-speed control of the amplitude of the terahertz waves transmitted at a specific frequency.